Shelf



FIG. 1 is a perspective view of a shelf showing my new design. The broken lines showing a mirror image shelf are included for the purpose of illustrating environment and form no part of the claimed design.

FIG. 2 is a top plan view of the shelf.

FIG. 3 is a bottom plan view of the shelf.

FIG. 4 is a front elevational view of the shelf.

FIG. 5 is a right side elevational view of the shelf; and,

FIG. 6 is a left side elevational view of the shelf. 

The ornamental design of a shelf, as shown and described. 